Corrosion behavior of carbon steel protected with single and bi-layer of silane films filled with silica nanoparticles


Autoria(s): SUEGAMA, P. H.; MELO, H. G. de; RECCO, A. A. C.; TSCHIPTSCHIN, A. P.; AOKI, I. V.
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

18/10/2012

18/10/2012

2008

Resumo

The electrochemical behaviour of carbon steel coated with bis-[trimethoxysilylpropyl]amine (BTSPA) filled with silica nanoparticles in naturally aerated 0.1 mol L-1 NaCl solutions was evaluated. The coating was prepared by adding different concentrations of silica nanoparticles (100, 200, 300, 400 and 500 ppm) to the hydrolysis solution and then a second layer without silica nanoparticles was applied. The electrochemical behavior of the coated steel was evaluated by means of open-circuit potential (E-OC), electrochemical impedance spectroscopy (EIS) and polarization curves. Surface characterization was made by atomic force microscopy (AFM), and its hydrophobicity assessed by contact angle measurements. EIS diagrams have shown an improvement of the barrier properties of the silane layer with the silica addition, which was further improved on the bi-layer system. However, a dependence on the filler concentration was verified, and the best electrochemical response was obtained for samples modified with 300 ppm of silica nanoparticles. AFM images have shown a homogeneous distribution of the silica nanoparticles on the sample surface; however particles agglomeration was detected, which degraded the corrosion protection performance. The results were explained on the basis of the improvement of the barrier properties of the coating due to the filler addition and on the onset of defective regions on the more heavily filled coatings allowing easier electrolyte penetration. (C) 2007 Elsevier B.V. All rights reserved.

Identificador

SURFACE & COATINGS TECHNOLOGY, v.202, n.13, p.2850-2858, 2008

0257-8972

http://producao.usp.br/handle/BDPI/18589

10.1016/j.surfcoat.2007.10.028

http://dx.doi.org/10.1016/j.surfcoat.2007.10.028

Idioma(s)

eng

Publicador

ELSEVIER SCIENCE SA

Relação

Surface & Coatings Technology

Direitos

restrictedAccess

Copyright ELSEVIER SCIENCE SA

Palavras-Chave #corrosion protection #silane film #silica nanoparticles #EIS #DIP GALVANIZED STEEL #ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY #ATOMIC-FORCE MICROSCOPY #AA 2024-T3 #RESISTANCE #PRETREATMENTS #AA2024-T3 #ELLIPSOMETRY #PERFORMANCE #INHIBITION #Materials Science, Coatings & Films #Physics, Applied
Tipo

article

original article

publishedVersion